Effects of fertilizer-modes on soil CO₂ emission in post-harvest paddy

The release rate of soil CO₂ and its factors were measured with CIRAS-2 portable photosynthesis system, then their relationship was analyzed to investigate the influences of the additional nitrogen fertilizer, phosphate fertilizer and arbuscular fertilizer on characteristics of soil CO₂ release in paddy. The results showed that: (1) The addition of nitrogen fertilizer resulted in soil CO₂release rate rising by 97.73% in 0 cm layer, and dropped by 39.93% and 31.36% in 10 cm and 20 cm layer, respectively. (2) While there was no significant difference between soil CO₂ release rates after the addition of phosphate fertilizer and of CK in 0 cm layer, the rate dropped 33.84% in 10 cm layer and rose 48.03% in 20 cm layer. (3) The additional arbuscular fertilizer had no significant influence on all three layers. (4) The related coefficients of soil CO₂ releasing rates and their factors in the same layers were affected by the fertilizer-modes, and its impact became lighter with the increasing of depth. Compared with nitrogen fertilizer and phosphate fertilizer, mycorrhizal fertilizer had no significant influence on the soil CO₂ release.